Apparatus for coiling wires,filaments and the like



March 10, 1970 H. SCHMID ETAL 3,499,276

APPARATUS FOR COILING WIRES, FILAMENTS AND THE LIKE Filed July 1'7, 1968 2 Sheets-Sheet 1 FIG. I

FIG.2

INVENTORS HANS SCHM ID HEIN RICH FELDHOFF EDELFRIED HAHN WOLFGANG MARTIN ATT'YS March 10, 1970 H. SCHMID ETAL 3,499,276

APPARATUS FOR COILING WIRES, FILAMENTS AND THE LIKE Filed July 17, 1968 2 Sheets-Sheet 2 FIG. 4

. i I ii i iiittfiz z ziztra INVENTORS: HANS SCHMID HEINRICH FELDHOFF EDELFRIED HAHN WOLFGANG MARTIN ATT'YS FILAMEN TS 6 Claims ABSTRACT OF THE DISCLOSURE Apparatus for coiling wires, filaments, bundles of filaments or yarns on a Winding core, consisting of a Winding core, a rotor provided with an eccentric feed bore for the filament and revolving about the winding core, and a feed screw which transports the filament over the winding core. The revolving rotor is formed with an axial recess which contains the feed screw having a shaft connected to" the rotor. The'recess further contains an armatune to which the winding core is attached and through which the shaft of the feed screw passes. The armature is mounted on a bearing on the shaft of the feed screw and is prevented from rotating by magnets located outside the rotor.

' The'invention relates to apparatus for coiling wires, filaments, bundles of filaments or'yarns on a winding core comprising a rotor provided with a feed bore and adapted to rotate about its winding core.

Coiled wires and filaments have numerous technical applications, for instance in the form of coil springs, incandescent lamp filaments, expandable supply leads, electrical resistance'coils as well as in the form of crimped fibers in the textile industry.

It has" already been proposed to coil wire in apparatus in which a rotor revolving about a winding core feeds the wire helically onto the winding core, each loop of wire pushing the preceding loop further along the core. Suitable gearingis arranged to transmit the rotary motion of the rotor'to the corein-the contrary hand of rotation so 'thatthe two elements revolve at the same speed but in 'contrary'direction's. Disadvantages of this arrangement are the multiplicity of gear wheels required for transmitting the rotary motion of the rotor to the winding core and forlreversing the hand of rotation and the resultant considerable mechanical wear as Well as the cost of production of the many interengaging machine elements. Difficulties in such a coiling machine are also experienced in the production of exactly single-layer coils, particularly when the winding speeds are high since the wire coil is advanced exclusively by the thrust of the following loop and this, frequently causes-trouble because the coils tend to climb over each other in several layers.

Another apparatus-is known which is used for crimping yarn. In this apparatus a yarn is coiledby a spinner onto a core which tapers in the, direction of yarn withdrawal and which is mounted inside the spinner. In this crimping machine the coiled yarn must be continuously manually withdrawn from the winding core, a procedure which also fails to ensure the formation of anniformly closely coiled single-layer helix. Moreover, no satisfactory way has as .yet been found of mounting the winding core in the rotating spinner; since there is always the risk of the core being entrained by'the spinner, in which case the yarn ceases to be coiled.

e v In another apparatus known in the art forcrimping synthetic yarns for" the production of curled hair for.

United States Patent ice dolls heads, a strand of filaments is wound by a rotating thread guide on a loosely mounted hollow core with a tapering extension terminating in a solid core. The coiled bundle of filaments is advanced by the thrust of the following loops or by feed means on the outside of the core, for instance in the form'of opposed rollers. The loosely mounted winding core is prevented from being entrained by the rotating thread guide by the Weight of a storage member for the coiled filaments adjoining the end of the core. It is a drawback of this arrangement that the limited weight of the storage member cannot prevent entrainment of the.winding core by the thread guide unless the winding pull is fairly low. However, since the advance of the coiled part of the threads by the following loops demands a considerable pull, the described apparatus cannot produce a precisely single-layer crimp. Moreover, the apparatus is unsuitable for processing continuous materials of higher fiexural rigidity, such as metals.

It is therefore an object of the present invention to provide apparatus for winding wire, filaments, bundles of filaments or yarns to form endless single-layer uniformly wound coils.

According to the invention, in apparatus for coiling wires, filaments, bundles of filaments or yarns on a winding core by means of a rotor which is provided with a feed bore and revolves about a winding core, the revolving rotor is formed with an axial recess containing a feed screw having a shaft connected to the rotor, whereas the free end of the feed screw projects from the recess, said recess further containing an armature to which the winding core is attached and through which the shaft of the feed screw passes, said armature being mounted on a bearing on the shaft of the feed screw and prevented from rotating by magnets located outside the rotor.

For purpose of minimizing eddy current loss in the rotor and for preventing this component from being heated, it is advisable to provide the rotor with axial slots which extend radially through the rotor in the region of the magnet pole shoes which partly embrace the external periphery of the rotor.

The stationary winding core may have the form of a wire hairpin embracing the feed screw with radial clearance. In order to produce coils of very small diameters it has been found best to provide a winding core in the form of a pin extending on one side of and parallel to the feed screw at a distance therefrom and projecting beyond the free end of the feed screw, the pin being maintained in said parallel position to the feed screw by magnets located at the end of the pin.

The feed screw may have for example the form of an anger or of a coil spring.

The invention will now be described in greater detail, by way of example, with reference to the accompanying drawings, in which FIGURE 1 is a longitudinal section of the coiling device, FIGURE 2 is a frontal view of the armature holding the -winding core, FIGURE 3 schematically represents the general layout, of the proposed coilingdevice, FIGURE 4 is a longitudinal section of a different embodiment of the coiling device, FIGURE 5 is a schematic representation of the general plan of the coiling apparatus illustrated in FIGURE 4 and of an associated after-treatment zone. v

The coiling apparatus shown in FIGURE 1 comprises a rotor 1 provided with a thread feeding bore 2, which rotor is rotatably mounted in the bearing 3 of a support means 4. An axial recess 5 in the rotor contains an armature 7 carrying a winding core which has the form of a wire hairpin 6 (see also FIGURE 2). The armature 7 is mounted on bearing 8 on the shaft 9 of a feed screw having the form of an anger 10. The shaft 9 of the anger is detachably or permanently affixed to the rotor 1 so that :he auger will rotate at the same speed as the rotor 1 vhen the latter revolves. The armature 7 is located beween the pole shoes 11 of an electromagnet 12, the pole ;hoes being positioned with radial clearance at the exter- 1a1 periphery of the rotor 1. The electromagnet 12 comarises coils 13 for generating a magnetic field and is afixed to the support means 4. When the rotor 1 revolves, :nergization of the electromagnet 12 causes the armature 7 and the attached winding core to be retained and the feed screw connected to the rotor can therefore freely evolve in the stationary armature 7. Suitable materials or the rotor are non-magnetic metallic or electrically in- :ulating materials, such as plastics or quartz. For the suparession of eddy currents in the motor and for preventing :he consequent generation of heat, the rotor may be )rovided with longitudinal slots which repeatedly interupt the paths of eddy currents penetrating the rotor.

With reference to FIGURE 3, the thread or wire is vithdrawn from a supply bobbin 14 and conducted over leflecting rollers 15 into the thread feeding bore 2 in the rotor 1. The rotor 1 is driven by a motor 16 and a fricion wheel drive 17. The eccentric exit of the thread feed- .ng bore 2 causes the thread to wind on the wire hairpin S forming the winding core when the rotor revolves. Be- :ause of the hairpin shape of the winding core, the wound hread also makes contact with the auger-shaped feed acrew which is mounted inside the axial recess of the rotor 1 and extends into the interior of the winding core. in the course of each revolution of the rotor 1, the thread wound on the auger is advanced by the pitch of one :onvolution of the screw thread so that an exact single- .ayer coil will be formed. The pitch of the feed screw is :onveniently so chosen that the loops of the coiled thread are closely adjacent. After the coiled thread has been pushed off the hairpin loop 6 of the winding core by the action of the feed screw it is taken over guide rollers 18 and wound on a take-up bobbin 20 driven by a geared notor 19.

In order to produce coils of very small diameters, such as internal diameters of 0.3 mm., it has been found useful to contrive the stationary winding core of the wind- .ng mechanism as shown in FIGURE 4, i.e., in the form )f a pin which is offset from and extends parallel to he feed screw beyond the free end of the feed screw. In Lhe embodiment shown in FIGURE 4 the feed screw is :onstituted by a wire coil 31. To permit the diameter of :he pin 30 to be made sufiiciently small for winding coils with internal diameters under 0.5 mm. it is, however, necessary to support the free end of the pin 30 constituting the core. Since support means rigidly connected to, or searing against, the pin would impede the feed of the :oiled thread on the pin, the support means for the pin 30 are magnetic means. For this purpose one or more nagnets 32 may be attached for instance by a bracket 33 :o the support means 4. By thus supporting and stabilizing :he pin, oscillations generated during the winding process and transmitted to the winding core cannot produce trou- Jlesome effects, whereas in the absence of the magnetic support the free end of the pin might Whip.

The mechanism according to this invention is particularly useful if the helically coiled wire or thread is to be submitted to an after-treatment as indicated in FIG- URE 5, for instance if it is to be lacquered or submitted to a thermal treatment for fixing the crimp that has been Jbtained. In the case of textile filaments the fixation of he crimp is usually indispensable in order to ensure that the crimp is retained after the thread has been pushed oil the core. As has already been described in detail with reference to FIGURE 3, the thread is withdrawn from a ;upply package 14 and guided into the thread feeding bore 2 of the rotor 1 by the guide rollers 15. In case of need the rotor 1 may be preceded by a preheating zone 26 :hrough which the thread travels. The rotor 1 is driven by a. motor 16 and a friction wheel drive 17. The revolving rotor '1 winds the thread about a core constituted by a thin pin 30 and, by means of the feed screw which has the form of a coil spring 31, the coiled thread is pushed along the pin 30 until it slides off its free end, whence it is taken over a guide roller 18 to run onto abobbin 20 driven by a geared motor 19. During its travel along the length of the pin 30 the coiled thread first passes through a heating chamber 21 which is provided with hot air supplied by an air circulating means 22 and conducted through a heating device 23 to heat the thread to fixing temperature. In a following cooling zone 24 the coiled thread is cooled to ambient temperature by a blast of cold air generated by a blower 25. In this manner the crimp produced by coiling the thread on the pin 30. is fixed so that it is retained when the thread leaves the pin. The magnets 32 required for stabilizing the pin 30, which extends to the end of the cooling zone, are located in the walls of the heating chamber 21 and of the cooling zone 24.

The apparatus illustrated in FIGURE 5 has proved particularly suitable for providing a crimp in single filaments or bundles of filaments of any cross-sectional shape consisting of thermoplastic synthetic materials, such as polyamides, polyesters and polyolefins. After having been coiled, the synthetic threads are heated in the heating chamber 21 of the fixing zone to temperatures at which they are plastically formable. In the case of crystalline thermoplastics, these temperatures may be in the-range between the crystallite melting point and a temperature which is about C. below the crystallite melting point. In a particularly advantageous procedure, filaments of say nylon-6 are heated to temperatures between and C. According to the nature of the synthetic material to be processed, it may be necessary to heat the filaments to a temperature at which they are plastically formable before theyare coiled. For this purpose, the rotor is preceded by a preheating zone 26 which heats the filaments to the desired temperature. Both in the preheating zone and in the heating chamber, care must be taken to ensure that the crystallite melting point is not exceeded in crystalline thermoplastics.

The advantages afforded by the apparatus according to this invention over known winding devices principally reside in the fact that it is simple in construction and requires substantially no maintenance and that the problem of supporting the winding core has been solved without the employment of supplementary drive means, gear wheels or other machine elements that wouldbe subject to wear. The proposed apparatus permits endless, exactly single-layer, closely wound coils to be produced. With reference to the choice of the diameter of the coil and 1. Apparatus for coiling wire, filaments, bundles of filaments or yarns on a winding core by means of a rotor provided with an eccentric feed bore and revolving about a winding core, which comprises a revolving rotor having an axial recess at the end at which the outlet of said eccentric feed bore is situated, said recess containing a feed screw having a shaft connected to the rotor, whereas,

the free end of the feed screwprojects from the recess, said recess further containing an armature to which the winding core is attached and through-which the shaft of the feed screw passes, said armature being mounted on at bearing on the shaft of the feed screw and prevented from rotating by magnets located outside the rotor.

2. Apparatus according to claim 1, in which the rotor is provided with axial slots which extend-radially through the rotor in the region of the pole shoes of the magnets,

said pole shoes partly embracing the external periphery of the rotor.

3. Apparatus according to claim 1, in which the startionary winding core is constituted by a wire hairpin embracing the feed screw with radial clearance.

4. Apparatus according to claim 1, in which the winding core constituted by a pin extends on one side of and parallel to the feed screw at a distance therefrom and projects beyond the free end of the feed screw, the pin being maintained in said parallel position to the feed 10 screw by magnets located at the end of the pin.

5. Apparatus according to claim 1, in which the feed screw has the shape of an auger.

6. Apparatus according to claim 1, in which the feed screw is a coil spring.

References Cited UNITED STATES PATENTS 

